Fibrous glass brush bristle



Feb. 8, 1966 a. J- MELCHER 3,233,270

FIBROUS GLASS BRUSH BRISTLE Filed Dec. 28. 1961 2 Sheets-Sheet 1INVENTOR. 64 as J. M54 men 1966 a. J. MELCHER 3, 3,

FIBROUS GLASS BRUSH BRISTLE Filed Dec. 28, 1961 2 Sheets-Sheet 2INVENTOR. 64 5 J Ma mm 4 T TORA/EYS United States Patent 3,233,270FIBROUS GLASS BRUSH BRISTLE Glee J. Melclier, Spokane, Wash, assignor toOwens- Corniug Fiberglas Corporation, a corporation of Delaware FiledDec. 28, 1961, Ser. No. 162,842 2 Claims. (Cl. 15-159) The inventionrelates to broom bristles having a fibrous glass base and a heavy outerlayer of plastic.

The majority of the machines for street cleaning utilize a largecylindrical broom revolving about a horizontal axis. These machines aregenerally pick-up sweepers in which the broom projects the debris upon aconveyor which carries it to a hopper.

Still in limited use is an older type of machine utilizing a similarcylindrical broom mounted at an angle to the direction of travel 'forsweeping the dirt into a windrow at the side of the pavement forsubsequent collection.

Split hickory, bass, palmyra, split bamboo, steel and more recentlysynthetic fibers of nylon, polystyrene and polypropylene have been usedfor the bristles in these brooms.

The median life of these cylindrical brooms with vegetable fiberbristles has been between 200 or 300 curb miles, a distance easilycovered within one week. Accordingly, the cost of a new broom and thelabor cost of removal and replacement is incurred at frequent intervals.The loss of the use of the machine for the replacement operationrequires additional equipment or delays the cleaning of streets.

Steel bristles are expensive, subject to corrosion, and areobjectionable because of the broken metal pieces which are shredded andleft behind. For air strip cleaning these metal remnants areparticularly dangerous as they are apt to be drawn into the air intakeof jet aircraft.

The cost of the synthetic bristles is even higher than that of steel.Further, these bristles are of materials which are inclined to absorbwater and are objectionable in this respect. They further do notgenerally have the desired flexibility.

An object of this invention is the provision of bristles of reasonablecost and which have a long life with uniform flexibility mostadvantageous for street sweeping.

More specifically, an object is to provide bristles of fibrous glass anda plastic overlay.

A further object is the provision of shaped brush segments in which thebristles are in fixed relation and in definite rows.

These as well as other objects and advantages are attained at least inpart by coating fibrous glass rovings with a hardenable plastic resinjust prior to winding the rovings upon a brush segment forming reel andsetting the resin after the rovings have been so arranged.

The invention will be explained more completely hereafter in connectionwith the drawings in which:

FIGURE 1 is a perspective view of apparatus designed for creating brushsegments;

FIGURE 2 is an enlarged sectional view of a completed double brushsegment on the apparatus of FIG- URE 1;

FIGURE 3 is a sectional view of two brush segments formed from thedouble segment illustrated in FIGURE 2 after it has been sheared alongits mid section and removed from the apparatus;

FIGURE 4 is a sectional view on an enlarged scale of a clampingarrangement for holding brush backing strips on longitudinal members ofthe reel of the apparatus of FIGURE 1;

FIGURE 5 is a perspective view of a core adapted to receive the brushsegments of this invention; and

FIGURE 6 is an end view of the core of FIGURE 5 with the brush segmentsmounted thereon.

Referring to the drawings in more detail the apparatus of FIGURE 1includes a base formed of end blocks 10 and 11. Two uprights 16 and 17of the frame blocks provide bearing apertures for the center shaft 21 ofa rotatable reel assembly 22.

The reel has a pair of longitudinal members 24 and 25 slightly more thansixty inches in length and spaced twenty-four inches apart. These arecylindrical in form and are secured at their ends to cross pieces 27 and28. Cross pieces 27 and 28 are fixed to shaft 21. On the outer end ofshaft 21 projecting through upright 17 is a pulley 34 driven by motor 36through motor pulley 37 and belt 39. Through this drive the reelassembly 22 is rotated at the desired speed.

On the near side of the apparatus, as seen in FIGURE 1, is adouble-threaded lead screw or cylindrical cam 41 rotatably journaled inbearings 42 and 43 supported on the frame blocks 10 and 11. The leadscrew 41 is turned by a belt 45 running between pulley 46 on the end ofthe lead screw and pulley 48 on the shaft 21 projecting through block11.

A carriage 50 has a pivotable lug (not shown) riding in the threading ofthe lead screw 41 and the carriage is moved lengthwise of the reel 22 bythe continuous engagernent of the lug with the lead screw. The carriage50 is further supported by a lateral leg 52 which slides upon the rail54 extending between frame members 10 and 11. Mounted on the carriage 50is a resin container 56.

Rovings 58, in this example five in number, are delivered from spools 63and directed under a coating roller 66 within the resin container afterpassing through spaced guide eyes 61. Exit guiding apertures 62 for therovings remove excess resin therefrom.

Other structural features of the apparatus will be described in thesubsequent explanation of the operation of the apparatus.

A preferred roving for the practice of the invention is one about .06 ofan inch in diameter and made up of sixty ends of strand composed ofcontinuous glass filaments with an average filament diameter of .00036of an inch and each strand having 13,500 feet of length, per pound.

To provide compatibility and good bonding characteristics between theroving and the resin, preferably utilized to coat the roving, the latteris finished with a chrome size. A well known type is a methacrylatechromic chloride complex, neutralized with ammonia.

As disclosed, five of the rovings 58 are drawn from spools 63. They areled through guide eyes 61 and under the resin applicator roller 64)within the container 56 which initially is at the left end of the leadscrew 41, as viewed in FIGURE 1. After being passed through the wipingguides 62 they are fastened to the end of one of the longitudinalmembers 24 or 25 of the reel 22 and are spaced apart about three-tenthsof an inch.

Held at each end of the longitudinal members by a U bolt 64, strap 65and nuts r36, as best seen in FIGURE 4, are pairs of brush back formingstrips 67 and 68 of arcuate cross section. These extend along oppositesides of the outer portion of each member 24 and 25.

The preferred resin is a general purpose polyester (containing monomericstyrene, diallyl phthalate, or vinyltoluene as cross-linking agents)catalyzed for fast curing at room temperature. Such a resin is availableat low cost and has the stiffness, strength, and resilience desired in abristle for street sweeping.

The resin should be sutficiently viscous for each roving to pick up aresin coating of a weight approximately equal to that of the roving. Inthis case, this is a coating about .02 of an inch thick which increasesthe diameter of the roving to approximately one-tenth of an inch.

The reel 22 may be turned, for instance, at thirty revolutions a minutewith the carriage driven at a speed whereby it makes a single traversefor every forty revolutions of the reel. This would space each turn ofcoated rovings about three-tenths of an inch apart, the same spacingexisting between the five individual rovings of each set, as they arewrapped upon the reel.

After the full traverse of the carriage 50, with the coated rovingswrapped around a five foot span of the reel, a rod or sticker aboutone-quarter of an inch in diameter is placed against each side of thewrapped form or shell of rovings alongside of the shaft 21 midwaybetween the longitudinal members 24 and 25. An original pair of suchrods 70 and 71 may be so mounted before the wrapping of the rovings isinitiated.

These rods are positioned through openings in spacers 72 and 74 fixed tothe cross pieces 27 and 28 and through openings in a spacer 73 fastenedto the shaft 21 at its center point. After a second pair of rods 77 areplaced along the outside of the first wrapping of the rovings, reel 22is again rotated and the carriage 50 with the resin container is movedin the opposite direction through the action of the lug on the carriagefollowing the opposite threading of the lead screw 41.

The second skein or layer of rovings formed by the second traverse ofthe carriage 59 is held about a quarter of an inch out from the firstlayer at the midpoint between the longitudinal members 24 and 25 by thepair of rods or stickers 77. This spacing establishes the final rowspacing arrangement of bristles in the brush.

After the second traverse of the resin carriage another pair of rods 79are positioned through the spacers in the holes adjacent to thosethrough which the pair 77 were inserted. This positions the next layerof rovings one-quarter of an inch out from the preceding layer.

For a total of thirteen traverses this procedure is repeated withadditional pairs of rods 7 9 inserted after each traverse. In theresulting composite shell of coated rovings wrapped on the reel therovings are closely contigu ous or in contact with each other as theypass over the longitudinal members 24 and 25 but form thirteen stratadiverging slightly from these members to a maximum spacing betweenstrata of one-quarter of an inch midway between the members.

While the resin is still sticky two narrow reinforcing Wooden slats 81and 82 are attached at the sides of the narrow ends of the shell ofrovings outside of the location of the back forming pieces 67 and 68. Across section of the reel with the roving shell forming a double brushsegment thereon is shown in FIGURE 2.

The plastic resin is allowed to harden and then rods 77 and 79 areremoved by drawing them out lengthwise through the apertures of spacers72, 73 and 74. The rods are waxed or carry some other releasing coatingwhich prevents the resin from adhering to them. To form two broomsegments the shell or double segment is cut by shears along both sidesof the line d-d, shown in FIG- URE 3 and the two brush segments 85 maythen be removed from the reel and appear as illustrated in FIG- URE 3.

The resulting five foot long brush segments 85 with bristles twelveinches in length have a continuous film of hardened resin between andimbedding the rovings around the base 87 of each segment. This is thickenough to have considerable strength to bond the bristles together andto hold the shape of the segment. The strips 67 and 68 and slats 31 and82 are also held firmly in place by this resin film and cooperate withit in serving as the brush backing or base 87.

A brush or broom core 90 particularly adapted for receipt of twelve ofthe brush segments 85 is illustrated in FIGURE 5. It has hubs 92 boredfor receipt of mounting and driving shafts for rotating the brushassembly. Extending lengthwise of the core and Welded to the hubs 92 andto a center reinforcing wheel 93 are twelve out wardly facing channels94. These are dimensioned to receive the bases of the brush segments. Tohold the latter firmly in proper positioning, retaining bars 96 ofsemicylindrical form are fitted against the curved portions of thestrips 67 and 68. These are tightened in place by bolts 98 passedthrough the bars 96, the resin film backing of the brush segments andholes 101 in the channels 94. The bolts are threaded into nuts 99 weldedto the underside of the channels.

The features of the invention include the traversing of the combinationroving feeder and coater, the positioning of the coated roving in rowsin final bristle arrangement and setting the resin thereafter, thecreation of a heavy, reinforcing, continuous resin film at the base ofeach segment, polyester coated glass strands as brush bristles and thebrush segment design and assembly upon a brush core.

The glass strand utilized for the bristle base may of course be ofvarious structures and sizes other than the rovings prescribed herein.With a lighter roving, closer spacing of the bristles of each row and ofthe rows themselves would be desirable. The term strand is utilized inthe claims to indicate any fibrous glass roving, yarn, strand or cordthat might serve as a bristle base.

Other resins than polyesters would be quite as adequate. These could beeither thermosetting or thermoplastic. In the prescribed quantity andviscosity of resin applied to the strands any of such resins shouldmerge to form a continuous, solid film encasing the contiguous glassstrands at the base of each brush segment. The consolidation of plasticresin and glass strands in this area creates, in effect, a plasticbacking reinforced with glass strands.

While a reel rotatable on a horizontal axis is considered the mostfeasible arrangement for practicing the invention, the reel could, ofcourse, be mounted for rotation on a vertical axis or one inclined tothe horizontal. The guiding of the rovings for wrapping upon a reeloperating so angled would be more troublesome but would not present toodifiicult a problem.

In another possible, but likewise unpreferred alternate method, the reelcould be held stationary and the coated roving guided around it. Theguiding means would be moved lengthwise of the reel as well as aroundit. In such an installation, it might be advisable to also have thecoating device and the spools of roving follow the movement of theguiding means.

Another modification of the invention involves wrapping the coatedstrands around the reel under sufficient tension and with the resincoating soft enough that each strand and its coating is flattened as itpasses over the spacing rods 70, 71, 77 and 79. This flattening extendsalong the strands away from their actual contact with the rods. With thestrands so shaped, the setting of the resin results in bristles ofsomewhat blade form. When incorporated in a cyclindrical brush assemblythe broadened sides of the bristles face the direction of rotation andpresent a greater area for driving contact with the debris or snow beingcollected.

Also, different spacing members may be utilized to vary the number andspacing of rows of bristles. The speed of production is another factorthat may be altered according to conditions. That given as an exampleherein in describing the apparatus is lower than would be normallyutilized.

Other modifications and substitutions will occur to those skilled in theart Without departing from the spirit of the invention and the confinesof the following claims.

I claim:

1. Brush bristles of multi-filament fibrous glass strand form which areindividually flattened at their free, outer end portions and held soflattened by a resinous binding material.

2. Brush bristles according to claim 1 in which there are generallycylindrical sections of the bristles merging into the flattened endportions.

(References on following page) References Cited by the Examiner UNITEDSTATES PATENTS Hendershot 15183 Remmele 15183 Peterson 3O0-21 Peterson300-21 Peterson 15179 X Woodling 15182 6 2,826,776 3/1958 Peterson15-179 2,845,648 8/1958 Peterson 15-159 2,984,053 5/1961 Peterson 15159X FOREIGN PATENTS 811,072 4/ 1959 Great Britain.

CHARLES A. XVILLMUTH, Primary Examiner.

1. BRUSH BRISTLES OF MULTI-FILAMENT FIBROUS GLASS STRAND FORM WHICH AREINDIVIDUALLY FLATTENED AT THEIR FREE, OUTER END PORTIONS AND HELD SOFLATTENED BY A RESINOUS BINDING MATERIAL.